questions on nonsleepable lock

John Baldwin jhb at
Wed Aug 15 11:15:31 PDT 2007

On Wednesday 15 August 2007 02:27:56 am Nex Mon wrote:
> Hello All,
> Can someone point me out or explain the technical details of this kernel
> panic:
> sleeping thread (tid 100093, pid 2676) owns nonsleepable lock
> panic: sleeping thread
> --
> --
> Is this caused by incorrect use of mutex or semaphores? Is this
> related to kernel scheduling? Can this be addressed at the
> user process? I've tried looking throught the freebsd mailing list
> archives and documentations but coudn't find a real good answer to
> solve or prevent this problem.
> Im using freebsd 6.1 with SMP enabled on a Xeon dual core hardware. The
> system has several busy applications running, But the load average is very
> minimal, around 8.55 and no process hogging the CPU. So I expect my system
> should be running smoothly without in problem.
> I appreciate any help.

I know there was at least one bug that could result in this, but the root 
cause was either a deadlock or use after free, etc.  It should be fixed in 
6-stable.  I can't recall further what it is though.

John Baldwin

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